Re: [discuss] [patch] x86_64: align and pad x86_64 GDT on page boundary

From: Andi Kleen
Date: Thu Dec 08 2005 - 15:14:49 EST


On Thu, Dec 08, 2005 at 11:42:32AM -0800, Ravikiran G Thirumalai wrote:
>
> - .align L1_CACHE_BYTES
> + /* zero the remaining page */
> + .fill PAGE_SIZE / 8 - GDT_ENTRIES,8,0
> +
> ENTRY(idt_table)

Why can't the IDT not be shared with the GDT page? It should be mostly
read only right and putting r-o data on that page should be ok, right?

> @@ -743,6 +743,13 @@
> };
> DECLARE_WORK(work, do_fork_idle, &c_idle);
>
> + /* allocate memory for gdts of secondary cpus. Hotplug is considered */
> + if (!cpu_gdt_descr[cpu].address &&
> + !(cpu_gdt_descr[cpu].address = get_zeroed_page(GFP_KERNEL))) {
> + printk("Failed to allocate GDT for CPU %d\n", cpu);
> + return 1;

Is this return really correctly handled? Doubtful.

-Andi

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